It was a vulnerability. We knew about it, but someone is exploiting it. We want our customers to be as secure as possible and install the patches.
Sophisticated hackers don't attack in a straight line, ... They weave between sites. If one of these sites strips off the source information and throws it away, there can be a break in the chain for investigators.
Global connectivity, lots of open sites, poor security at some, and lack of tracing ability create an environment where if you are up to no good, you can flourish.